There are two airports close to Gothenburg, Gothenburg Landvetter Airport (GOT) and Gothenburg City Airport (GSE).
Landvetter airport is the main airport. It is serviced by a large number of airlines.
Despite the name, Gothenburg City Airport is less convenient to get to and from, since the airport bus runs less frequently. Its main advantage is that it is serviced by budget airlines, mainly Ryanair. See the Wikipedia pages linked to above for more airline and destination information.

Because of the excellent connections between Gothenburg Landvetter Airport (GOT) and Chalmers, arriving early in the morning of the first day and leaving in the evening of the last day is entirely possible. The airport bus runs every 15-20 min, and takes 20 min from GOT to Korsvägen, and from Korsvägen to Chalmers, trams 6 and 8 run about every 10 min, taking only a few minutes. The airport bus to GSE only goes from the main station (Nils Ericsson Terminal). Upon arrival at GSE a bus will be waiting outside; getting to the airport is slightly less convenient. There will be only one bus going 2h20min before your flight from GSE. The bus takes about 20min, so expect some spare time at the airport.

From experience, we know that it's better to be on time the first day and leave early the last day, rather than the opposite.

Stena Line operates ferries from continental Europe along two routes. Fredrikshavn (Denmark) can be reached in 2h on a high-speed craft and in 3.15h on a car ferry. Kiel (Germany) can be reached in 14h. The terminals are situated near the city center.

The Landvetter Airport Bus stops at Korsvägen, where you can take trams 6 or 8 to Chalmers. Tram 7 takes you from the Central Station to Chalmers. See the map of the tram and trunk bus network for more information. The Chalmers stop is located somewhat below the center of the map.

You can buy tram and bus tickets onboard (from the driver on buses, and from a vending machine which only accepts coins on the tram) for SEK 20 per travel. If you think you will need the tram or bus more often, you can buy a bus card for SEK 100 where each travel will cost about 15 SEK. You can *not* buy those in the bus, but in most magazine shops (look for blue/yellow "pressbyran" signs.) Inside the bus you'll have use those green boxes, put your card in there and press button "2" if you're traveling inside the city.

SGS Veckobostäder rents rooms in a student housing complex close to Chalmers. The price depends on the length of stay. 3 nights cost SEK 1140 for a single room, 1450 for a double room, and 1690 for a four bed room. The web site is mostly in Swedish. E-mail vb@sgsveckobostader.se or call +46 31 333 63 90.

Nice Bed & Breakfast is also located close to Chalmers. Single rooms from SEK 425 per night, double 495, triple 695 and four bed room from SEK 995 per night. Kosmikus reports that currently (March 25) there seem to be no more single or double rooms left.

Quality Hotel Panorama is located close to Chalmers. Single rooms from SEK 490 per night, and double rooms from SEK 840 per night.

Slottsskogens Vandrarhem is about 10 minutes by tram away from Chalmers. Prices are SEK 195 for a bed in a 3 to 6 bed room or SEK 225 for a bed in a 2 bed room. If you stay for four or more nights it could be worth buying a membership card, which gives you a discount of SEK 45 per night. To get to Chalmers you use tram line 6 until Chalmers station.

Vandrarhemmet Linne is right next to Slottskogens. Prices are similar: SEK 190 for a bed in a 3 - 6 bed room, SEK 200 for a bed in a 2 bed room. The website is in Swedish, but if you press on "boka rum" (="book room") you'll find an English interface.

Scandic Rubinen. Hotel at about 20 min walking distance from Chalmers. Tram 7 (direction Tynnered) and tram 10 (direction Guldheden) will take you from the tram stop Valand to the Chalmers main entrance.

Scandic Opalen. Hotel at about 25 min walking distance from Chalmers. Trams 6 (dir Länsmansgården), 8 (dir Frölunda) and 13 (dir Marklandsgatan) take you from the Scandinavium tram stop to the Chalmers main entrance.

The Hackathon will be held from 10am to 6pm each day, with dinner after at local venues. From experience, we know that it is a good idea to be on time the first day in order not to miss the introductions of all the attendees.